LED implanted under the skin

Researchers in the United States, China, South Korea, and Singapore have collaborated to develop a flexible, ultra-thin, sheet-like inorganic light-emitting diode (LED) and photodetector that can be implanted under the skin for medical monitoring and activation of photosensitive drugs. And other biomedical applications.

Optical Image: An array of 8 x 8μ light emitting diodes (ILEDs) was placed on a thin layer of polydimethylsiloxane (PDMS) substrate in the on state and in a deformed state.

The study, led by John Rogers, was at the University of Illinois at Urbana-Champaign. The study was published today in the journal Nature Materials and developed a flexible array. The 2.5 μm thick, 100 x 100 μm square area is much smaller than any commercially available array. Their printed circuits are printed directly on a rigid glass substrate and then transferred to a cheap, biocompatible polymer called polydimethylsiloxane (PDMS), which creates a sieve array of light-emitting diodes. And photodetectors.

This polydimethyl methacrylate sheet has sufficient elasticity to allow the circuit to still function when twisted or stretched up to 75%. Rogers said that most of the research focused on organic light-emitting diodes (OLEDs) are extremely sensitive to water and oxygen, but this elastic array is encapsulated in a thin layer of silicone rubber, which makes them waterproof and can perform well. Implanted or completely immersed in biological fluids.

This design also eliminates the mechanical limitations that affect the device, which is usually due to a rigid semiconductor wafer, which is the wafer support device.

The researchers successfully tested the light-emitting diodes. They integrated a thin piece into the vinyl glove's fingertips and dipped them in soapy water. They also implanted an array under the skin, which was done in animal experiments. For light emitting diodes, potential biomedical applications have various implants that can monitor wound healing, use in diagnostic or spectroscopy, or control drug transfer. The use of light to trigger the transfer of drugs is the case in photodynamic drug therapy. They can also be used for luminescent sutures, or implanted plasma crystals, or for use in robots.

Rogers recently founded a company in Cambridge, Massachusetts. The company is committed to the commercial application of this new technology. This is a goal that he believes is "incredibly attractive." Rogers said he hopes that this technology will produce Influence, this is the ultimate goal, has been promoting the work.